Face Distortion

Hey there,
I was wondering if anybody would be able to point me in the right direction. I want to be able to distort peoples faces in images (either still images or video).




the people in this is exactly what i want to do. It looks to me like their heads are completely fixed but their body can move and in some cases, it looks like the top half is one video and the bottom half is another video, judging by the angles but it is completly seamless.
also, chris cunninghams ps2 ad




for that, i believe they used either infero or flame.
i dont know what application would be appropriate for this sorta work?

any help would be greatly appreciated
cheers!

Joe